OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are randomized to 1 of 4 arms. Arm I: Patients receive low-dose CCI-779 IV over 30 minutes weekly. Arm II: Patients receive high-dose CCI-779 IV over 30 minutes weekly. Arm III: Patients receive low-dose placebo IV over 30 minutes weekly. Arm IV: Patients receive high-dose placebo IV over 30 minutes weekly. Treatment continues in the absence of disease progression or unacceptable toxicity. Patients who develop progressive disease while receiving placebo may cross over to the equivalent dose of CCI-779. Quality of life is assessed at baseline; at weeks 4, 8, 12, 24, and 36; and at final/cross-over visit. Patients are followed every 3 months.